NORTH SHORE GAS SOUTH PLANT

EPA ID# ILD984809228
Last Updated: January, 2015

Site Description

The North Shore Gas (NSG) South Plant former Manufactured Gas Plant (MGP) site ("South Plant site") is located on Pershing Road in an industrial/commercial area of Waukegan, Lake County, Illinois. The site includes the 1.9-acre former MGP facility along Pershing Road and adjacent areas where MGP residuals are now found. These adjacent areas, which total around 20 additional acres, include the Akzo Nobel Aerospace Coatings facility, Waukegan Port District (marina, administration and maintenance buildings, along with parking lots), the Elgin, Joliet & Eastern railroad tracks and right-of-way, and the city of Waukegan right-of-way. The South Plant MGP facility itself is owned by North Shore Gas Company, a subsidiary of Integry Energy Group (Integrys).

MGPs were industrial facilities that produced gas from coal, oil, and other feedstocks. MGPs started operating in the U.S. in the early 1800s, typically in urban areas where gas was needed for lighting, cooking, and heating. The processes used to produce the gas also produced waste and by-products such as tars, purifier waste, oils, sludges, and acidic waste. Disposal of waste and spills and leaks often resulted in contaminated soil and groundwater. MGPs were often located near waterbodies and sediment contamination is also common.

The NSG South Plant former MGP facility was constructed in 1897 by the Waukegan Pipeline Service Company and purchased by North Shore Gas in 1900. The plant was operational from 1898 to 1946 except for a stoppage from 1927 to 1935, and was razed in 1951. On-site features included a coal gas condensing building, a purifying building, a generator building and a laboratory. Four tar wells and five storage tanks, three for gas and two for oil, were also located on-site.

The NSG South Plant site is being addressed under EPA's Superfund Alternative Sites program.

Site Responsibility

The NSG South Plant site is being addressed through potentially responsible party (PRP) actions under federal and state oversight.

Threats and Contaminants

Groundwater samples collected at the site from 2001 to 2003 and on adjacent properties from 2003 to 2005 contained volatile organic compounds (VOCs), consisting mostly of benzene, toluene, ethylbenzene, and xylene (BTEX), semi-VOCs [primarily polycyclic aromatic hydrocarbons (PAHs)], cyanide, and metals. Visible hydrocarbons were observed at or below the water table both on-site and on the adjacent Waukegan Port District and Akzo Nobel properties to the east. Free-phase tar has been measured at thicknesses up to 1.5 feet in wells on the site and at thicknesses of more than 5 feet in wells 560 feet downgradient of the site on the Waukegan Port District property and within 160 feet of Waukegan Harbor. Tar is being recovered from monitoring and recovery wells located on-site and on the Port District property. However, public water in the area is obtained from Lake Michigan (the water intakes for the city of Waukegan are approximately 5,000 feet southeast of the site) and no private potable wells are located within the vicinity of the site.

Numerous on-site borings have encountered visible soil impacts from former site operations. Strong odors, a visible sheen, and soils saturated or coated with tar or dense non-aqeuous phase liquids (DNAPL) have been observed both on-site and on the adjacent Waukegan Port District and Akzo Nobel properties to the east. BTEX, SVOCs, cyanide, and metals have been detected in soils on the site and the adjacent properties.

Cleanup Progress

North Shore Gas (NSG) was merged into Integrys Energy Group, LLC (Integrys). In 2006, EPA was approached by Integrys, the site owner and PRP, with a request to address thirteen former MGP sites in Illinois including the South Plant site in Waukegan. On July 2007, EPA and Integrys entered into an AOC to conduct RI/FS activities at the South Plant and North Plant sites in Waukegan, IL. The 2007 AOC allows for a streamlined approach to site investigation and remedy development. Some benefits of the agreement include the use of multi-site documents, a mechanism to review the adequacy of past work, and flexible scheduling and prioritization of resources to address the "worst contaminant problems first." By the end of 2008, all of the multi-site documents had been approved, and site-specific work had begun at the sites. RI field work at the South Plant was initiated in 2008. As of December 2013, 12 rounds of quarterly groundwater monitoring have been conducted, along with 2 rounds of vapor intrusion sampling in the Waukegan Port District and Akzo Nobel properties, and sediment/surface water sampling in the marina and the lake.

Investigations and Remediation Previously Performed

Numerous site investigation reports have been produced for the site and/or for the surrounding properties dating from 1991 through 2005. These investigations included a CERCLA Screening Site Inspection (SSI) performed by Illinois EPA (IEPA). Limited soil remediation was conducted at the site in December 2003 through February 2004 that included the excavation and off-site disposal of impacted soils located above the water table. Approximately 19,250 tons of impacted soils were removed from the site and backfill was imported to replace the excavated soil. A plastic liner was placed at the water table elevation to protect the imported backfill from potential contamination. This remediation effort did not address impacted soils located beneath the water table and did not include excavation of all impacted soils identified above the water table, but rather focused on those soils exhibiting the greatest degree of impacts. No soil remediation activities have been conducted at the adjacent Port District and Akzo Nobel properties.

Current Progress

In December 2012, Integrys submitted a draft RI report to EPA for review and approval. EPA approved the RI report in January 2014. EPA is currently reviewing a draft focused feasibility study (FFS) for addressing DNAPL, which continues to be the source of contamination in area groundwater. EPA projects that a final FFS will be released by late spring 2015 along with a proposed DNAPL cleanup plan for public comment.